Telegraphy



(No Model.)

S. D. FIELD.

TELEGRAPHY.

No. 892,914. Patented Nov. 18, 1888.

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nrrnn STATES PATENT TELEGRAFHY.

SPEUIPICATION forming part of Letters Patent No. $92,91 dated November 13 1888.

Application filed August 24, 1858. Serial No. 283,641.

To aZZ whom it may concern:

, Be it known that I, STEPHEN DUDLEY FIELD, a citizen of the United States, residing at Stockbridge, in the county of Berkshire and State of Massachusetts, have invented cer tain new and useful Improvements in Telegraph Systems; and I do hereby declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a novel system of telegraph y, which I have termed a diplex telegraph, but which, as will be seen, is capable ofbeing duplexed in any manner well known in the art to form a quadruplex system, or may be combined with any ofthe well-known methods of transforminga duplex system into a sextuplcx or multiplex system.

The invention comprises a novel form of transmitting apparatus and a novel form of receiving apparatus adapted thereto; and it consists in the arrangement and combination of devices and instrumentalities, substantially as hereinafter more fully described and claimed.

In the accompanying drawings, which form part of this specification, Figure 1 is a diagram illustrating the entire system of transmitting apparatus, line, and receiving apparatus in one of the simple forms of the invention. Fig. 2 is a transverse view of the supplementary tongue or arm of the relay of the receiving apparatus alone.

In carrying out my said invention I propose to use three dynamo-electric generators so arranged that two of them will be adapted to send current of one kind over the line with the electro-motive force of one alone or that of the two combined in series, while the third dynamo is arranged to be connected into line, so as to send a current the reverse as to direction compared with the two former machines; and I use a single key and a double key in order to give perfect facility to two operators to operate their keys in a manner totally independent of each other. The receiving apparatus is designed to operate in such manner that when either of the transmitting-keys is operated a corresponding local sounder at the receiving end will be actuated according to (No model.)

which of the two keys is worked at the moment, and when both keys happen to be worked simultaneously then both the local sounders at the receiving end will give the signals correspondingly.

To these ends my invention is as follows:

First, as to the transmitting apparatus, I use two keys, both of the continuity-prescrving type, one being a single key and the other a double key. The single key IL is formed so as to normally close the contacts 1 and 2 and have the contacts 3 and open, and by pressing the knob of the key the contacts 3 and at are closed, while the contacts 1 and 2 are opened. The double key K is formed on one leg with a similar set of contacts, of which 5 and 6 are closed when the key is idle and contacts 7 and S are opened; but by operating the knob of the key the contacts 7 and S are closed and the contacts 5 and 6 are opened, while a similar set of contacts on the other leg are arranged so that when the kcy is idle the contacts 9 and 10 are open and the contacts 11 and 12 are closed; but when the key-knob is depressed contactsQand 10 become closed, while contacts 11 and 12 are simultaneously opened.

The circuits are as follows: The line comes to the contacts 1 and 3 of key K. From contact 2 a local circuit is established with the contacts 10 and 12, and includes a fixed resistance, Itfor example, one hundred ohms. From the key K a circuit is run to the posi tive pole of the shunt-wound dynamoelectric machine D and a fixed resistance, It, again inserted, (in the instance given one hundred ohms.) From the negative pole of the dynamo D a circuit is carried to the contacts 5 and 7; but from the key K and therefore contact 8, a circuit is carried to the positive pole of a second shunt-wound d ynamoelectric machine, D and from the negative of the same machine a circuit is carried direct to earth. Earthcircuits ar also established from contacts 6 and 11, and included in'each of said circuits is a fixed resistance of, say, two hundred ohms, and marked, respectively, It and It, and such earth-circuits are, for convenience, shown as being joined to the earth-circuitof dynamo D". From the second arm of the key IQ, and therefore from its contact 9, a circuit is established to the negative pole of the dynamo D, such circuit including a fixed resistance, R of, say, one hundred ohms, and the positive pole of such dynamo D is connected direct to earth along with the other earth-circuits. Of course, if desired, each of the foregoing earth-circuits may be established independently; but such is unnecessary. Upon now following out the operations of the two keys it will be seen that in their normal position, as shown in Fig. 1, the circuits of respective dynamos are all open. On depressing thekey K, contacts 1 and 2 are broken and contacts 3 and 4 are closed. This immediately sends an impulse of positive current over the line, which returns by way of ground through resistance R, contacts 6 and 5, and the negative pole of the dynamo D, supposing at the moment that the key K is idle. If, on the other hand, key K happens to be depressed at the same instant, the contacts 7 and 8 are closed and contacts 5 and 6 are opened. Therefore the dynamos D and D are thrown into series, and, starting from the positive pole of D the currentgoes to contacts 8 and 7, negative pole of the dynamo 1), positive pole of the same, resistance R, contacts 4 and 3, and thence to line, returning by way of ground direct to the negative pole of dynamo D We have therefore the condition that if key K is depressed alone (the dynamos all being of substantially the same potential-say one hundred volts each) a positive current of one hundred volts is sent over the line, and if it happens that key K is depressed at same time a positive current of two hundred volts is sent over the line. On the other hand, if while key K is idle key K is depressed, neither of the dynamos D or D has a closed circuit, and are therefore inoperative; but dynamo D will operate through resistance R contacts 9 and 10, resistance R, contacts 2 and 1, to line, sending a negative current of one hundred volts, and the positive pole of said dynamo D is closed to the return earth. WVe have therefore three conditions, viz: key K alone operating, sending a particular current over the line, or key K" alone operating and sending a different character of current over the line, or, finally, both-keys operating together, in which an entirely different current is sent upon the line, so as to actuate both receiving-instruments.

The various fixed resistances above alluded to are located as named for the purpose of equalizing the electrical resistances of various circuits under the conditions on which they are operated in carrying out the invention. Taking the figures given above, then We have on the depression of the key K one hundred volts positive in line when key K is idle or up, and on the depression of key Kflwhen key K is idle or up, a current of one hundred volts negative in line, and when both keys are depressed at same timewe have two hundred volts positive in line. It now remains to obtain an apparatus which will select these diffcrent currents in such manner as to receive the signals in the manner in which they are sent. For this purpose 1 construct a receiving-relay as follows:

M represents a tubular magnet having the adjustable core O,provided with thumb-nut N, by which means the core may be readily introduced or withdrawn to any desired extent. The edge of the walls of the magnet M is slotted at diametrieal points for the reception of the tongue 0, which carries a coil of fine wire, a, and is pivoted below in a suitable manner. A similar tongue, d, is independently pivoted and carries a coil, b,of fine wire of such diameter as to easily fit over the coil a. The two tongues are so situated relatively that their coils a and b are substantially in the same plane, and both to a greater or less extent surround the projecting end of the core 0 of the magnet M, and they therefore occupy a position. directly in the lines of force which pass from the core 0 to the external walls of the magnet. This field of force is rendered very intense by the form of the magnet M and the use of as large a current as may be found necessary, supplied by a local battery, 13''.

The coils a and bare difierentially connected in series, so that current passing through the coil a will pass through coil 1) in a reverse direction, so that the tendency of the coils a and b,when energized by a sufficient current from the line,is to cause the tongues c and d to separate from their normal position or approach more closely together. The line comes in to one of the coils-say a-passes thence to the other coil, and from it goes to ground, as shown.

The local circuits of the relay are as follows: Tongue (Z carries a contact, 13,which in normal position is closed against contact 14, which is fixed in any suitable manner on the base of the relay,and from contact 14 a circuit is carried around to a pivoted arm, 6, whose pivotal axis is vertical. The tongue d is drawn against the contact 14 by means of the spring 9, which is adjusted by the adjusting-screw 7:, suitably arranged. The tongue 0 carries a contact, 15, which is normally closed on a contact, 16, carried by the arm 0, and these contacts 15 and 16 are independently maintained in closed relation by an isolated spring, f. At the outer extremity of the arm 0, which is shown on lapping over the tongues c and d, is a contact, 18,which is closed normally against afixed contact, 17, by means of the spring h, adjusted by a suitable adjusting-screw, j. A circuit is run from the tongue d through a local battery, L B,and a sounder,S, thence around to a fixed contact, 17. Another local circuit is run from a tongue,c,through alocal battery, L D ,a sounder,S and thence likewise around to the fixed contact 17.

Thus constructed the operation of the re ceiving apparatus will be as follows: The polarity of the magnet M will be so arranged with relation to the different currents that the tongues c and d will be drawn toward each other by negative line-current and will be repelled from one another by a positive line-current of IIO normal potential. When the key K is do pressed, sending one hundred volts positive into line, contacts 13 and 14 separate by reason of repulsion of the coil 1), and this makes the corresponding signal on the local sounder S. When the key K is depressed,contacts 15 and 16 separate by reason of repulsion by the magnet M of the coil a, and this opens the circuit of the local sounder S and the signal is distinguishable. 'When both keys K and 1' are depressed together, (which occurs when each of the operators desires to send an impulse over the line at the same instant,) the resulting double current of two hundred volts positive is sufficient to overcome the spring h, and the contacts 17 and 18 are separated by the increased attraction of the magnet M for coil a, and therefore the two local-sounder cir cuits are opened and the sign al is distinguished by each of the receiving operators. Therefore all necessary requirements are observed, and the system is completely practical with the devices I have shown above.

Of course it is obvious that the mere form is not essential to the success of the invention, and the same may be varied to any desired extent without departing from the spirit of my invention.

It will be observed that the springfis not attached to any fixed adjusting-screw, but is self-contained between the tongues c and the arm 0, and therefore it of itself has no tendenoy to affect the solidity of contact between the points 17 and 18, which would be the case It will also be observed that the adjustment of magnetic field for the coils a. and 1) lies entirely in the construction of the magnet itself; and I therefore in this instance do away with a series of resistances in the circuit of the energizing-battery.

I claim as my invention- 1. In a system of telegraphy, a transmitting apparatus comprising, in combination with a line and earth, the armatures of three shuntwound dynamo-electric generators, two continuity-preserving keys located between said armatnres and the line, and fixed resistances located between each of said armatures and earth, substantially as described, whereby said armatures are adapted two of them to send impulses independently or jointly, and the third independently only.

2.. A. telegraphrelay comprising two or more nested coils susp nded in and induct ively energized by a common field of force and provided with levers and contact-points for the local circuits, substantially as described.

3. Atelegraplrrelay comprising two coils differentially included in the line and sus pended in substantially the same plane in an annular field of force and provided with levers and contact-points.

4. The described triple-contact relay, consisting, in combination with two sounder-circuits and their batteries, of two coils differentially connected in series and suspended in a magnetic field, two pivoted tongues carrying said coils, and a third tongue or arm so arranged with contacts in three pairs, sub stantially as described, that a given currentin one direction will separate one pair, the same current in the opposite direction will separate another pair, and a stronger current in the first direction will separate a pair forming a part of both the other circuits.

5. A telegraph-relay having as its sensitive part two dii'ferentiallyconnected coils and three pairs ofloeal-circuit contacts, one pair of which forms a path for each of the remaining pairs, in combination with two local-sounder circuits, and means for communicating the movements of said coils to the respective pairs of contacts.

6. In a telegraph-relay, the combination of the pivoted tongues c d, supporting the coils a I) in a magnetic field, and having the contacts 13 and 15, the fixed contacts 1st and 17, and the transverse arm 0, having contacts 16 and 18, substantially as described.

7. In a telegraph-relay having a vibrating or pivoted tongue, 0, provided with a contact, 15, the combination therewith of a pivoted tongue or arm, 6, having a contact, 16, and an insulated spring, f, adapted to normally hold said contacts together, while permitting a linr ited movement to both tongue 0 and arm 0.

In testimony whereof I my signature in presence of two witnesses.

STEPHEN DUDLEY FIELD.

\Vitnesses:

0. H. Winnie, Carts. E. Evans. 

